Refrigerator mounted filter systems connected directly to a water supply exist. For example, U.S. Pat. Nos. 6,574,984, 6,337,015, 6,303,031, 5,956,967, 5,819,547, 5,490,547, 5,484,538, 5,320,752, and U.S. patent application Ser. Nos. 10/445,372 and 10/643,669 published as US 2004/0007516 and 2004/0129617, respectively, disclose water filtration systems for refrigerators. These systems can be as simple as individual filters placed on a water line, wherever the manufacturer can find space for them. This type of system is cumbersome for manufacturers to install.
Currently, most of the refrigerator's manufacturers have water dispensers on their side by side refrigerators but they are through the door execution, they do not work with the low water line pressures and do not deliver anti-microbial filtration/purification. Some of them also have developed a through the door top mount execution, but they are manual fill and do not have any filtration. A top mount external dispenser also exists.
Thus, refrigerator mounted dispenser systems connected directly to a water supply exist. For example, U.S. Pat. Nos. 6,810,682, 6,763,976, 6,574,984, 6,425,425, 6,003,734, 5,971,213, 5,956,967, 5,862,952, 5,857,596, 5,819,547, 5,813,246, 5,791,523, 5,737,932, 5,743,106, 5,683,015, 5,542,265, 5,096,095, 4,207,994, and 3,934,757 disclose water dispenser systems for refrigerators. However, a combination of a refrigerator mounted filter system with a refrigerator mounted dispenser system which enables an effluent from said combined system exhibiting a log 6 bacteria reduction and a log 4 virus reduction with pressures as low as 0.35 kg/cm2 (5 psi) is not readily available.
In many countries, the water pressure in the homes varies extensively from house to house, block to block and city to city. The generalized use of water roof top tanks allows a pressure of about 0.70 kg/cm2 (10 psi), for a house of a single story. The pressure in apartments will depend on the height at which the water roof top tank is. This way, most of the houses do not have sufficient water pressure to allow the use of the typical filters of water without the necessity of a pump or another system.